Streptomycin treatment of genital carriers of Leptospira in experimentally infected sheep on different estrous phases.

Leptospirosis in ruminants presents as a chronic disease that causes several reproductive disorders leading to severe economic losses. The current recommended treatment can be efficient to eliminate the renal carrier state, however little is known about the effect of this drug in removing the genital carrier state and the hormonal influence on it. A total of 12 primiparous sheep experimentally infected with a strain of Leptospira santarosai serogroup Sejroe, FV52 strain, were used and distributed as group A (estrus; n = 5), group B (metaestrus; n = 4) and group C (control; n = 3). At D0, groups A and B were treated with streptomycin (25 mg/kg) single dose. Samples of cervicovaginal mucus (CVM) were collected on days 0, 3, and 35 post-treatment, while uterine fragment (UF) samples were collected on days 3 and 35, for PCR. Even after antibiotic treatment, all groups presented infected animals, at D3 and D35, with no significant difference between the treated and control groups. Based on these results, it was conducted a second protocol of treatment with streptomycin, IM (25 mg/kg) for three consecutive days, which was 100% effective to eliminate the genital carrier state; therefore, that protocol should be recommended.